Lock type excess flow valve



May 12, 1959 P. A. SMITH ETAL 88 LOCK TYPE EXCESS FLOW VALVE Filed Aug.4, 1958 ZShets-Sheet 1 INVENTORS f a m By 5M%W Qfi ATTORNEYS. I

May 12, 1959 P. A. SMITH ET AL LOCK TYPBEXCEISS FLOW VALVE 2Sheets-Sheet 2 Filed Aug. 4, 1958 LOCK TYPE EXCESS FLOW VALVE Peter A.Smith and Philip L. Johnson, Marshalltown,

Iowa, assignors to Fisher Governor Company, a corporation .of IowaApplication August 4, 1958, Serial No. 752,784 1 Claims. or. 137-517This invention relates generally to an excess flow valve, and moreparticularly to an improved lock type excess flow valve structure foruse in the storage and dispensing of liquefied petroleum gas.

In liquefied petroleum gas systems, such as those employing a storagetank of liquefied propane and butane gases, it is often necessary toprovide a supplemental outlet or supply means. Such outlets requireexcess fiow check valve structures therein for insuring regulated supplyflow therethrough. Ordinarily, when a liquefied .petroleum gas tank isfirst installed, the user has no immediate need for the supplementaloutlet which is customarily provided, but such outlets are desirable inorder to permit possible future expansion of the installed system. Inpractice, such supplemental use requirements may not be necessary untilas long as several years following initial installatidnof the tank. Whenit becomes necessary to unplug such supplemental outlet connections andadd a new user, coupling for the supply of gas to another point of use,it is very important to insure utmost safety and complete control of gasflow through the excess flow check valve of the outlet connection unitilthe new line couplingsfare completed.

There has been a marked trend in recent years toward vapor space fillingin connection with liquefied petroleum gas storage, and many domesticstorage systems omit the use of the previously conventional dip pipe forcommunicating the access fitting with the liquid content of the tank. Inorder to effect liquid transfer or system evacuation in suchinstallations, it is necessary to provide a safe and reliable means forcoupling a shut-off valve to the tank fitting without interruption ofthe system service.

Although excess flow valve structures have been suggested in the past,for application to liquefied petroleum gas systems, as in our copendingapplication Serial No. 669,188, filed July 1, 1957, it has often beennecessary to insure that the threaded coupling of a pipe nipple to theexcess flow valve device, for either transfer and evacuation purposes orfor added gas dispensing purposes,

must be made with careful attention to the number of pipe thread turnsin order to insure proper valving action and safety control.

It is a primary object of the present invention, therefore, to provide anew and improved lock type excess flow valve, providing a safe andefiicient connecting means for both vapor and liquid transfer fromliquefied petroleum gas storage tanks during system service.

It is another object to provide a lock type excess flow valve which isnot limited to the use of a correctly threaded pipe nipple or a specialadaptor to insure that correct thread engagement is attained.

Further objects and advtantages of this invention will become apparentasthe following description proceeds, and the features of novelty whichcharacterize this invention will be pointed out with particularity inthe claims annexed to and forming part of this specification.

A preferred embodiment of the invention is shown in the accompanyingdrawing, in which:

Figure 1 is a fragmentary side elevation view of an excess flow valve,embodying the present invention, mounted in a wall of a conventionalliquefied petroleum gas storage tank;

Figure 2 is a vertical cross sectional view of the valve ofFigure 1; and

Figure 3 is a horizontal cross sectional view taken substantially asindicated along the line 33 on Figure 2;

Figure 4 is a vertical cross sectional view, similar to Figure 2, of amodified form of excess flow valve having a scalable equalizing portshowing the parts thereof in locked relation;

Figure 5 is another vertical cross sectional view of the valve of Figure4, showing the parts thereof in an open flow relation; and

Figure 6 is a horizontal cross sectional view taken substantially asindicated along the line 6-6 on Figure 4.

Referring now more particularly to Figures 1 to 3 of the drawing, Wehave designated generally at 10 a first embodiment of a lock type excessflow valve constructed in accordance with the present invention. InFigure 1, the valve 10 is shown threadedly coupled. to a suitable bossor fitting 12 of an outer wall portion of a conventional liquefiedpetroleum gas storage tank 14. For purposes of illustration, the valvehas been shown oriented in a typical bottom mounting in the cylindricalshell of a conventional LPG storage tank, and it will be understood thatthe same valve may be readily adapted for bottom mounting in generallyhorizontal alignment in the end or head wall of a tank, and also inassociation with 'a dip tube for top mounting in vertical alignment inthe top wall of a tank.

, Referring now to,Figures 2 and 3, the valve 10 comprises a generallycylindrical hollow body 16 having an axially elongated collar portion 18of reducted diameter at one end thereof. A chamber 20 is defined withinthe body 16 in coaxial alignment with a smaller diameter bore 22 withinthe collar. portion 18 thereof. An intermediate tapered shoulder 21 isdefined between the chamber 20 and bore 22. The upper end of the body 16is internally threaded at 24 to receive the correspondingly threadedneck of a pipe plug or cap 26. A gasket or seal ring 28 insuresfluid-tight coupling of the cap 26 within an outlet opening 30 of thechamber 20. It will be apparent that upon removal ofthe cap 26, theoutlet opening 30 and threaded portion 24 will be adapted to receive acorrespondingly threaded nipple or coupling member.

t The collar 18 is externally threaded for cooperation with a threadedboss or tank opening fitting, as indicated at 12 in Figure 1. The freeend of the collar 18 defines therein a tapered outlet opening 34'terminating in a rounded annular valve seat 36. An intermediate annularshoulder 37 is defined between the opening 34 and the bore 22thereabove.

A poppet 38 provides a frusto-conical valve surface 40 adapted tosealingly engage the valve seat 36. The poppet 38 is centrally securedto the lower threaded end 42 of an elongated stem member 44 having anenlarged head portion 46 at the upper end thereof. An annular shoulder45 is defined intermediate the ends of the stem 44. It will beunderstood that the stem 44 may vary depending upon the requirements ofmanufacturing convenience. For example, the stem 44 may be formed as anintegral member with the poppet 38, and the head 46 may constitute aseparate member connected to the stem 44.

A retainer member is generally indicated at 48, and is normally disposedwithin the chamber 20. The retainer 48 provides a transverse bottom wall50 havi'nga plurality Patented May 12, 1959 p of flow apertures 32therein. A generally cylindrical side wall 54 extends upwardly from thebottom wall 50 and defines an outwardly enlarged annular bead 56terminating in a top edge defining an enlarged opening 58. The diameterof the side wall portion 48 is slightly less than that of the bore 22for slidable movement therein. The diameter of the bead 56 issubstantially larger than that of the bore 22 but slightly less thanthat of the chamber 20 so as to enable slidable movement within thelatter while providing limited engagement against the shoulder 21. Thestem 44 slidably extends through a central opening 59 in the retainerbottom wall 50, and the enlarged head portion 46 thereof extendssubstantially laterally beyond the periphery of the opening 59 forlimiting engagement against the bottom wall 50.

A'compression spring 60 engages the retainer bottom wall 50 at its oneend, and engages a stern guide 62, which is seated upon the annularshoulder 37, at its other end. It will be understood that the stem guide62 may be formed as an integral spider portion of the body collar 18 ifdesired for manufacturing convenience, and has been shown as a separatemember for illustration purposes only. The stem guide 62 provides aplurality of flow ports 64, and a central opening 65 through which thelower end 42 of the stem 44 slidably extends. An excess flow spring 66is disposed in compression between the stem guide 62 and the poppet 38.An equalizing pressure port 68 extends through the poppet 38 for bleedflow communication of'the tank interior with the bore 22 and chamber 20.

In the normal assembled relation of parts as shown in Figure 2 of thedrawing, the compression spring 60 exerts a sufficient lifting forceagainst the retainer 48 so as to raise the stem 44 against the biasingforce of the excess flow spring 66 and insure tight seated engagement ofthe poppet valve surface 40 against the annular valve seat 36. Thisserves to lock all fluid flow through the valve except for therestricted leakage through the equalizing port 68 of the poppet 38.

When the pipe cap 26 is removed, leakage of liquid or vapor may bereadily detected through the equalizing port 68. A pipe nipple with asuitable cooperating shutoff valve, or a shut-off valve device having anintegral pipe thread portion, may then be threaded into the outletopening 30 at 24. As such a member is threaded into the upper chamber20, it will engage the retainer 48 and slide it downwardly in a guidedmanner within the bore 22. This serves to release the head 46 of thestem 44 from engagement with the retainer bottom wall 50, and to enablethe excess flow spring 66 to effect an opening movement of the poppet38, thereby permitting fluid flow between the valve surface 40 and theseat 36. Under conditions of excessive rate of flow from the opening 34to the opening 30, the bias of spring 66 will be overcome in thewell-known manner to interrupt flow'by seating of the valve surface 40upon the seat 36.

Any amount of over trave of the retainer 48 due to extra length ortolerance variations in the engagement of the pipe threads within thebody 16 will have no effect on the operation of the present valvestructure. Travel of the excess flow check valve poppet 38 to its openflow position will be limited by engagement of the shoulder 45 upon thestem guide 62.

In order to remove the valve from service, it is only necessary .toremove the previously coupled shut-01f device and slug the excess flowvalve. In this way, the retainer 48 will be permitted to return to itsnormal position substantially fully within chamber in response to thebiasing action of the compression spring 60. The cap 26 may then bereplaced to complete the seal of the fluid bleed escape permitted by theequalizing port 68.

Referring now to Figures 4 to 6 of the drawing, We have designatedgenerally at 10' a second embodiment of a lock type excess flow valve,similar to the valve 10 previously described but embodying the addedfeature of a sealable equalizing port.

The valve 10 comprises a generally cylindrical hollow body 70 internallythreaded at its upper end to receive a closure cap 72, and externallythreaded at its lower end to define a collar portion 74. An elongatedchamber 76 is defined within the body 70 and terminates at the oppositeends thereof in outlet openings 78 and 80. The outlet opening 80provides a rounded annular valve seat 82. A poppet 84 provides afrusto-conical valve surface 86 adapted to sealingly engage the valveseat 82. An elongated stem member 88 is secured to the poppet 84 at itslower end and terminates in an enlarged head portion 90 at its upperend. A retainer member 92, having a perforated bottom wall 94 and anapertured top wall 96, is normally disposed within the upper end of thechamber 76 for slidable movement therein. The stem 88 slidably extendsthrough a central opening 98 in the bottom wall 94 of the retainer, andthe enlarged head portion 90 thereof extends substantially laterallybeyond the periphery of the opening 98 for limiting engagement againstthe bottom wall 94.

A compression spring 100 engages the retainer bottom wall 94 at its oneend, and engages a stem guide member 102 at its other end. The stemguide member 102 is seated upon an internal annular shoulder 104 of thehollow body 70, but may be formed as an integral spider portion thereoffor manufacturing convenience. The stem guide 102 provides a bore 106 ofsubstantial length surrounding the stem member 88 for slidable guidingsupport thereof. The stem guide 102 is formed with a plurality of radialreinforcing ribs 108 and a plurality of flow apertures 110 arrangedcircumferentially between the ribs 108. An excess flow spring 112 isdisposed in compression between the stem guide 102 and the poppet 84. Anannular shoulder 114 is formed on the stem member 88 for limitingengagement against the upper end of the stern guide 102.

The structure of the modified form 10' as thus described correspondssubstantially identically in form and function with the embodiment 10 ofFigures 1 to 3. In certain practical applications of excess flow valvesin liquefied petroleum gas systems, however, it may be desirable tomaintain sealing closure of any internal pressure equalizing portsprovided by the valve structure until such time as a pipe nipple or ashut off valve is threaded into the outlet opening for releasing thelocking engagement between the retainer 92 and the poppet stem member88. In order to accomplish this purpose, the valve 10' provides ascalable equalizing port in place of the open port 68 of the valve 10.

An elongated bore 116 extends through the poppet 84 and alongsubstantially the full length of the stem member 88, terminating withinthe enlarged head portion 90 thereof. A small port 118 extends from thebore 116 angularly to the under surface of the head portion 90. AnO-ring or similar resilient sealing element 120 annularly surrounds thestem member 88 intermediate its head portion 90 and the apertured bottomwall 94 of the retainer 92.

In the normal assembled relation 'of parts as shown in Figure 4 of thedrawing, the compression spring 100 exerts a sufiicient lifting forceagainst the retainer 92 so as to raise the stem 88 against the biasingforce of the excess flow spring 112 and insures tight seated engagementof the poppet valve surface 86 against the annular valve seat 82. At thesame time, the O-ring 120 is tightly engaged between the lower surfaceof the stem head portion 90 and the retainer bottom wall 94. In thisway, the O-ring 120 effects sealing engagement and closure of the port118.

Upon removal of the cap 72 and insertion of a threaded pipe nipple 122or a corresponding portion of a shut off valve into the outlet opening78, the retainer 92 will be slidably shifted downwardly within thechamber 76 against the pipe of the spring 100, asindicated in Figure 5of the drawing. The stem member 88 will be released so as to enablevalve opening of the elements 82 and 86 in response to the spring 112.The sealing compression against the O-ring 120 will also be released,enabling equalizing flow to pass freely through the bore 116 and port118.

While there have been shown and described two particular embodiments ofthis invention, it will be obvious to those skilled in the art thatvarious changes and modifications may be made therein without departingfrom the invention and, therefore, it is intended in the appended claimsto cover all such changes and modifications as fall within the truespirit and scope of the invention;

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. A lock-type excess fiow valve comprising an openended hollow tubularbody providing a valve seat adjacent its one end, a valve memberoperatively associated with said valve seat for sealing engagementthereagainst, a valve stem within said body extending from said valvemember toward the other open end of said body, retainer meansreciprocable within said body, said valve stem being slidably supportedby said retainer means for relatively free movement in a valve-closingdirection and for limiting retention in a valve-opening direction, firstresilient biasing means normally urging said retainer means and valvestem in a valve closing direction, and second resilient biasing means oflesser force than said first biasing means normally urging said valvemember in a valve opening direction, said retainer being normallypositioned by said first biasing means to eifect seating of said valvemember against said valve seat, whereby said valve memher and secondbiasing means cooperate to perform an excess flow valving action onlyupon shifting of said retainer means toward said one end of the body torelease said valve stem for free slidable movement.

2. A. lock-type excess flow valve comprising an openended hollow tubularbody providing a valve seat adjacent its one end, a valve memberoperatively associated with said valve seat for sealing engagementthereagainst, a valve stem within said body extending from said valvemember toward the other open end of said body, retainer meansreciprocable within said body, said valve stem being slidably supportedby said retainer means for relatively free movement in a valve-closingdirection and for limiting retention in a valve-opening direction, guidemeans within said body slidably supporting said valve stem, firstresilient biasing means normally urging said retainer means and valvestem in a valve-closing direction, second resilient biasing means oflesser force than said first biasing means normally urging said valvemember in a valveopening direction, said retainer being normallypositioned by said first biasing means to effect seating of said valve'member against said valve seat, whereby said valve member and secondbiasing means cooperate to perform an excess flow valving action onlyupon shifting of said retainer means toward said one end of the body torelease said valve stem for free slidable movement, and stop meansprovided by said valve stem for engagement with said guide means tolimit the extent of valve member opening.

3. A lock-type excess flow valve comprising an openended hollow tubularbody providing a valve seat adjacent its one end, a valve memberoperatively associated with said valve seat for sealing engagementthereagainst, a valve stem within said body extending from said valvemember toward the other open end of said body, retainer meansreciprocable Within said body, said valve stem being slidably supportedby said retainer means for relatively free movement in a valve-closingdirection and for limiting retention in a valve-opening direction, firstresilient biasing means normally urging said retainer means and valvestem in a valve-closing direction, second resilient biasing means oflesser force than said first biasing means normally urging said valvemember in a valveopening direction, said retainer being normallypositioned by said first biasing means to eifectseating of said valvemember against said valve seat, whereby said valve member and secondbiasing means cooperate to perform an excess flow valving action onlyupon shifting of said rotainer means toward said one end of the body torelease said valve stem for free slidable movement, and bleed port meansfor restricted fluid flow into said valve body when said valve member isin its closed position.

4. A lock-type excess flow valve comprising an openended hollow tubularbody defining a chamber at one end, a flow communicatingbore ofrelatively smaller cross section at the other end, said body defining avalve seat at the outlet opening of said bore, a valve member operativeto seal against said valve seat, a valve stem within said body extendingfrom said valve member toward said chamber, retainer means reciprocablewithin saidchamber and slidable into said here; the end ofsaid valvestem opposite said valve member being slidably supported by saidretainer means for relatively free movement in a valve closing directionand for limiting retention in a valve opening direction, first resilientbiasing means normally urging said retainer means and valve stem in avalve closing direction, and second resilient biasing means of lesserforce than said first biasing means normally urging said valve member ina valve opening direction, whereby said valve member and second biasingmeans cooperate to perform an excess flow valving action only uponshifting of said retainer means into said bore to release said valvestem for free slidable movement.

5. A lock-type excess flow valve comprising an openended hollow tubularbody defining a chamber at one end, a flow communicating bore ofrelatively smaller cross section at the other end, and an intermediateannular shoulder therebetween, said body defining a valve seat at theoutlet opening of said bore, a valve member operative to seal againstsaid valve seat, a valve stem within said body extending from said valvemember toward said chamber, retainer means reciprocable within saidchamber and slidable into said bore, the end of said valve stem oppositesaid valve member being slidably supported by said retainer means forrelatively free movement in a valve closing direction and for limitingretention in a valve opening direction, first resilient biasing meansnormally urging said retainer means and valve stem in a valve closingdirection, and secondresilient biasing means of lesser force than saidfirst biasing means normally urging said valve member in a valve openingdirection, said retainer means providing stop means adapted to engagesaid annular shoulder for limiting sliding movement thereof into saidbore against the force of said first resilient biasing means, whereby torelease said valve stem for free slidable movement and enable saidsecond biasing means and said valve member to perform an excess valvingaction.

6. A lock-type excess flow valve comprising an openended hollow tubularbody providing a valve seat adjacent its one end, a valve memberoperatively associated with said valve seat for sealing engagementthereagainst, a valve stem within said body extending from said valvemember toward the other open end of said body, retainer meansreciprocable within said body, said valve stem being slidably supportedby said retainer means for relatively free movement in a valve-closingdirection and for limiting retention in a valve-opening direction, firstresilient biasing means normally urging said retainer means and valvestem in a valve-closing direction, second resilient biasing means oflesser force than said first biasing means normally urging said valvemember in a valve-opening direction, said retainer being normallypositioned by said first biasing means to effect seating of said valvemember against said valve seat, whereby said valve member and secondbiasing means cooperate to perform an excess flow valving action onlyupon shifting of said retainer means toward said one end of the body torelease said valve stem for free slidable movement, and bleed port meansextending through said valve member for restricted fluid flow into saidvalve body when said valve member is in its closed position.

7. A lo'ck-type excess flow valve comprising an openended hollow tubularbody providing a valve seat adjacent its one end, a valve memberoperatively associated with said valve seat for sealing engagementthereagainst, a valve stem within said body extending from said valvemember toward the other open end of said body, retainer meansreciprocable within said body, said valve stem being slidably supportedby said retainer means for relatively free movement in a valve-closingdirection and for limiting retention in a valve-opening direction, firstresilient biasing means normally urging said retainer means and valvestem in a valve-closing direction, second resilient biasing means oflesser force than said first bias-t ing means normally urging said valvemember'in a valve opening direction, said retainer .being normallypositioned by said first biasing means to effect seating of said valve vmember against said valve seat, whereby said valve member and secondbiasing means cooperate to perform an excess flow valving action onlyupon shifting of said retainer means toward said one end of the body torelease said valve stem for free slidable movement, and bleed port meansextending through said valve stem for restricted fluid flow into saidvalve body when said valve" memberis in its closed position, said bleedport means including sealing means supported intermediate said valvestem and said retainer means and operative to close said bleed portmeans when said valve stem and said retainer means are in limitingengagement with each other.

No references cited.

